Those are definitely important. Do not skip on safety gears.
Helmet try getting the ones with ece22.06 rating.
Jacket, pants,gloves, boots you can get benkia/komine/rs taichi for asian fitting.
Also dont forget rain coat, since raining season is almost here

Riding gear with budget <700 won't have abrasion resistant.. those are found on higher end gear.
Even so they are good enough, check my review on an accident I had while wearing komine jacket, rs taichi gloves and benkia pants
https://forum.lowyat.net/index.php?showtopi...#entry109075491

Since its a used bike it could be because of wear and tear.
Check if handlebar screws are properly tightened.
Handlebar grip might also need to be replaced something with softer compound like Domino A010.
Gloves with thick fabric at the palm and finger area could help too.

Other factor could be that you are gripping the handlebar too tight. This is common to new rider.
Loosen the grip and make it that you can turn the handlebar with just your fingertips.
Relax your shoulders so that you arent pressuring your wrist.